Archive: Mar 2023

Key Properties of Oxygen Free Copper

Oxygen-free copper is a type of copper that is combined with carbon and carbonaceous gasses. It is made by melting copper and mixing it with the carbon content and gasses in an electrolytic copper refining process. Subsequently, most of the oxygen contained in the copper is removed, ultimately forming a compound made with a minimum purity of 99.99% copper and oxygen content of less than or equal to 0.0005%.

This pure copper content makes it more durable, thermally and electrically conductive. These and other enhanced properties make oxygen-free copper a popular choice for many applications across a wide range of industries.

Properties of Oxygen-Free Copper

The properties of oxygen-free copper include:

Increased Tensile Strength, Elongation, and Hardness

One of the key properties that make this material popular is its improved tensile strength of 222-385 N/mm2, with a proof strength rate (to 0.1% deformation) of 60-325 N/mm2. This material is also capable of elongation of 60-4% and features a hardness range of 45-115 HV.

High Conductivity

When it comes to conductivity, oxygen-free copper features an average conductivity of 102% along with a guaranteed value of 101% as per IACS. Thermal conductivity also ranges from 386 to 394 W/m°C.

Improved Corrosion and Softening Resistance

Unlike standard copper, oxygen-free copper’s higher purity provides increased corrosion resistance. It also exhibits resistance to softening, meaning it can operate successfully at temperatures of up to 105°C for as long as 20 to 25 years. In addition, it has a high melting point of around 1083°C (1981°F).

Higher Density

If you require metal with greater density, oxygen-free copper is also beneficial in this area. This metal boasts a density of 8.89-8.94 g/cm3 or 0.321-0.323 lb/in3.

Optimal Workability

Oxygen-free copper is extremely brazeable, and solderable. C10100 copper is fabricated at temperatures as high as 760 to 871°C (1400 to 1600°F), and it is excellent for both hot and cold working. Annealing of this grade is also performed at temperatures between 371 to 649°C (700 to 1200°F).

Other properties of oxygen-free copper include low volatility under high vacuum, invulnerability to hydrogen embrittlement, and high impact strength.

Grades of Oxygen-Free Copper

For different applications, there are two main grades of oxygen-free copper available, including:

C10100 Oxygen-Free Electronic Copper (Cu-OFE)

With silver removed, C10100 oxygen-free electronic copper contains 99.99% copper, with oxygen reduced to 0.0005%. This grade is made from pure copper cathode, which is poured beneath a protective gas atmosphere. It boasts around 1% higher electrical conductivity compared to C10200 oxygen-free copper, along with superior corrosion resistance. It’s frequently used for high-quality audio and video systems.

C10200 Oxygen-Free Copper (Cu-OF)

This grade contains 99.95% copper and boasts excellent purity. It’s worth noting that no copper is ever 100%.

Applications/Industries Served by Oxygen-Free Copper

Some common industries and applications for oxygen-free copper include, but are not limited to:

  • Automotive, industrial, and electrical industries
  • Klystrons
  • Coaxial Cables
  • Wave Guides
  • Electrical Conductors
  • Microwave Tubes
  • Bus Conductors
  • Busbars
  • Anodes for Vacuum Tubes
  • Lead-in Wire
  • Tubing
  • Transistor Components
  • Billet Mold Tube
  • Automotive Rectifiers
  • Copper for Glass Seals in Electrical Appliances
  • High Resistance-Ratio Cryogenic Shunts
  • Powder Metallurgy Extrusion Cans

Contact Sequoia Brass & Copper Today

If you’re looking for superior copper materials that exhibit increased strength, durability, workability, and other benefits, consider using oxygen-free copper from Sequoia Brass & Copper. We are a leading supplier of oxygen-free copper as well as other top-grade nonferrous metals. Our experienced professionals will work with you throughout the metal procurement process to make sure you get only the products you need. We regularly monitor, review, and upgrade our Quality Management Systems to maintain consistent quality, ensure the satisfaction of our customers, and meet all statutory and regulatory requirements.

For more information about our oxygen-free copper materials, request a quote or contact us today.

Copper vs. Brass

When choosing a material for your project, it’s important to select one with the appropriate qualities to best support your application. Understanding the difference between brass and copper is essential when making these decisions. At Sequoia Brass & Copper, we specialize in providing high-quality materials, including oxygen-free copper, brass, and bronze, for metal fabricators. If you’re considering brass vs. copper, we can help you determine which one is right for you.

What Is Brass?

Brass is a copper/zinc alloy, though other metals (like iron, aluminum, silicon, or manganese) may be added to enhance specific characteristics and colors. A higher level of zinc or silicon will make the brass stronger, for example, while the addition of iron will give it magnetic qualities.

Brass is highly formable with a low melting point, and it’s non-ferromagnetic, making it easy to separate to recycle. Desirable brass properties include high corrosion resistance, which can be improved even further by including a larger amount of manganese in the brass, and good thermal and electrical conductivity. However, it is likely to crack if placed under significant stress.

Brass is commonly used in a variety of applications:

  • Decorative items and trim
  • Musical instruments
  • Pipes and tubing
  • Electrical components

What Is Copper?

Copper is a naturally occurring metal that’s highly malleable, though it’s not very hard nor strong. It’s non-magnetic and resists corrosion, with good thermal, conductivity, excellent electrical conductivity and low chemical reactivity. Because it retains its electrical and mechanical properties even at cryogenic temperatures, copper finds a number of uses across industries:

  • Coins
  • Electrical equipment
  • Construction and roofing
  • Automotive
  • Pipes and plumbing
  • Industrial machinery
  • Telecommunications
  • Marine applications

What Is the Difference Between Brass and Copper?

While copper is a naturally existing base metal, brass is an alloy: a man-made combination of copper and zinc. Brass can feature a variety of characteristics depending upon how much zinc and other metals are mixed with the copper, but brass and copper properties are similar. Copper is antimicrobial, which makes it useful in high-touch applications and medical facilities. Because brass contains copper, it retains those antimicrobial properties. Both materials will oxidize and develop a patina, which for some applications is a desired decorative look. If not, you can seal the brass or copper item to prevent exposure to air.

With its high conductivity, copper is a popular choice for wires and electrical components, while various types of brass find more uses in industrial and consumer goods. Take a look at these key differences between the materials to help you determine whether brass or copper is a better choice for your application:

  • Copper is completely electrically conductive, while a brass alloy offers some electrical resistance, depending on the amount of each alloyed metal.
  • Brass offers better corrosion resistance.
  • Copper has a higher melting point: 1084° C compared to brass at 900° C to 940° C.
  • Brass is harder than copper, and the more zinc the brass alloy contains, the harder it will be.
  • Brass features higher machinability, weldability, yield strength, and shear strength.
  • Copper is usually more expensive than brass, though it can depend on the specific alloy and the material quality.

Whether you go with brass or copper will depend on the environmental conditions and unique stresses your finished product will face. Each metal offers advantages for specific applications.

At Sequoia Brass & Copper, we source copper, bronze, and brass alloys in sheets, tubes, bars, plates, and rods, and we specialize in hard-to-find shapes and alloys. Since 1983, we’ve been committed to working with only high-quality metals while offering competitive pricing, clear communication, quick service, and expert guidance for our clients. With our years of experience in the industry with both domestic and international metal sources, we can connect you with the materials you need for projects of all sizes. Contact us to learn more, or request a quote for your project.

Copper vs. Bronze

Since 1983, Sequoia Brass & Copper has been serving the metal fabrication industry with high-quality bronze, copper, brass, and other nonferrous metals in various shapes and forms. We adhere to extremely strict quality and purity standards so that our clients can rely on us to meet and exceed their requirements.

Due to their distinct reddish color, bronze and copper fall into the category of “red metals”. While bronze is a copper-based alloy, bronze exhibits more hardness than pure copper and typically contains other elements that produce various properties. While these metals feature many similarities, they each have unique characteristics that make them suitable for different applications.

What is Bronze?

Bronze is copper alloy that contains primarily copper and tin. Bronze can also contain other elements, including manganese, phosphorus, aluminum, arsenic, and silicon in various quantities to produce different properties.


Bronze alloys are preferred in a wide variety of applications, including:

  • Marine. Due to its corrosion resistance, bronze is a popular choice for boats and other marine-exposed applications such as ship propellers and fittings.
  • Sculptures. Its muted gold tone and aesthetic appearance make bronze a common material for sculptures and other pieces of art.
  • Musical instruments. Bells, cymbals, and other musical instruments are often made of bronze.
  • Electrical connectors. Certain varieties of bronze alloys provide great electrical conductivity, making them useful in a wide range of electrical applications such as connectors and springs.
  • Bearings and bushings. Bronze alloys are good for bushings and bearings in high-stress environments because of their minimal metal-to-metal friction levels.
Bronze Properties

Bronze alloys are reddish-brown in color and possess properties that enable them to be used in many applications, such as those listed above. The properties of bronze include:

  • Hard and brittle, although it is less brittle than cast iron
  • Melting point of 950° C
  • Low metal-to-metal friction levels
  • Excellent electrical conductivity
  • Corrosion-resistant

What Is Copper?

Copper is a ductile, malleable, reddish metal that is commonly alloyed with zinc, tin, nickel, and brass to yield different properties. Copper and copper alloys provide excellent electrical and thermal conductivity, which makes them popular for use in electronics and a wide range of other uses. It can also be easily soldered, or brazed.

Copper Applications

Copper’s many desirable features make it suitable for a wide range of applications, including:

  • Coins
  • Electrical equipment
  • Construction
  • Roofing and plumbing
  • Industrial machinery
  • Telecommunications
  • Marine
Copper Properties

Properties of copper include:

  • Excellent thermal conductivity
  • Excellent electrical conductivity
  • Resistant to corrosion
  • Good biofouling resistance
  • Good machinability
  • Retains mechanical and electrical properties at cryogenic temperatures
  • Non-magnetic
  • Naturally antimicrobial

What are the Differences Between Bronze and Copper?

There are many differences between bronze and copper. Bronze is an alloy, or mixed metal, consisting primarily of copper as well as various other elements. Because bronze is commonly alloyed with metals like tin, it is much harder than pure copper. While bronze is easier to fuse and cast, copper has an impressive ability to fight bacteria, making it suitable for industries such as medical and food processing.

Partner With Sequoia Brass & Copper

Both bronze and copper have an impressive range of properties that make them suitable for use in various applications and industries. Sequoia Brass & Copper is committed to providing our clients with the highest quality metals in sheets, plates, rods, bars, and tubes. To learn more about bronze, copper, or other metals we provide, contact us or request a quote today.